Apparatus for dispensing highly volatile liquids



Nov. 17, 1936. HNWADE 2,061,013

APPARATUS FOR DISPENSING HIGHLY VOLATILE LIQUIDS Filed March 11, 1935 .HENR'Y N. WADE TOR/V5 V //v l EN ml? @402 OJ. g

Patented Nov. 17,

2,.CLO13 maaa'ros FOB DISPENSING HIGH-I VOLAEHLE LIQUIDS HenryllWadaLos'AngeleaOaliLaflgamWo Pukhill-Wade, Incorporated, Ina Angdn. alif.,acorporationof0aliloania Applieatimllarchlhlfiiseflallialm liquldsofhkhvaporpressurqsuchasthe liquefied pehnlemn gas which consists largely of propane and/or butane, are often stored in relativelylargequantltyinordertobedispensed into truck tanks. automotive vehicle fuel tanks and other snmller containers. For economy of ground space and more particularly for reasons ofsafety,thestoragetanksareusuallyplaced undergrounithisbeinginfactalegalrequirement in most cities. From these buried tanks theliquidiswlthdrawnbymeansofapump which mustusually deliver the liquid at a pressuremateriallyahovethevapor pressure.

Theuselorthispurposeot a'pumpplaced at orabovethesurfaceoftheearthisattended withsomediilculty. Theliquidbodyinthe storage tank rapidly comes into vapor-pressure equilibrium with the overlying vapors. Thereafter, any attemli to draw liquid from the tank by suction lift from an elevated pump causes moreorlessvaporiaaflonofthe liquidinthe mnnpsuctionplnmthepressureontheliquidin this pipe heir: necesarlly brought below the vaporpresmeintheveryactofproducingthe suction. This vaporization renders the operationotanypumpineilicientanduncertainand mayenflrely l'evmttheuseofthecentriiugal typeoif annpwhidiismostdesirableforhandlingextrernelyvolatile liquids.

This diillcultv maybe avoided by locating the pressm'emmpitselfatorbelowthebottomof thetank,asinadceppit,inawellinsidethe tank,orinawellexterlortothetankandconnectedwithitllyll p Either ofthese arrangementahowevenisundulyexpensiveasto instalhtim andrenders repairs or replacements awkwardanddimcult.

Theohjectotmylnventionistoprovide means forliftingtheliquidfromtheundergmundbody toapmnpaictionatasuhstantiallyhigherlevel, ortoasecondliquidbodylocatedaboveand communicatirg with the pump suction, without permittirg vaporization of the liquid on its way to the pump, which may thus be operated at fullei'ilcimcyandinareliablemanneratall times.

The form of the invention contemplated in thepresenta mlicationisilhrstratedintheattached drawing, which shows in a diagrammatic manner a suitable assemblage of apparatus.

Referringtothedrawing, l isaclosed storage tank placed materially below the grolmd level indicatedatl. Aflllingpipe3havingahand valve I provides for introducing the volatile liquidbodyindicatedat 5.

A relatively small secondary tank or receiver 6 is placed above ground and is pipe connected atitslowerendwiththesuctlonotapump I, this pump having a discharge P p I provided with a valve I.

The upper end of the receiver is connected withthevaporspaceinthetopottank l by meansofapipe ll havhuravalve ll. Ahand operated vent valve I! is also aranged at the top of the receiver.

Atapointbetweenpumplandvalve 9,discharge pipe I is provided with a branch pipe l3 having a. valve ll. This pipe is carried upwardly toalevelmateriallyahovethetopoi the receiver and then downwardly through the top of tank I to apointnearltshottom. Atthislevel it connects with the jet side of a jet-and-Venturi type eductor l5, which has its suction opening in communication with the interior of the tank. The eductor discharges through a pipe it which passrsthroughthetopofthetankandisconnected into the recdver at a point materially v below its upper end.

This apparatus functions in the following manner. The main tank l'is first filled through pipe 3,valvesland ll beingclosedandvalve l2 opentoventvaporuntilreceiveriisfilledby displacement from tank Ii. Valve i2 is then closedandvalve ll opcnedto equalizethe vapor pressures in tank I and receiver 6, after which the filling of the tank my be completed without venting vapor.

To make a delivery from tank I, the receiver being now filled to the levd at which it overflows through pipe l6 and the pump suction being thus flooded, the pump is started and valve 9 adjusted to maintain a prmrre on the pump discharge higher than the vapmpresure of the liquid. Valve II is thcn'opmed suiliciently to permit a small proportion of the liquid discharged by the pump to pass through pipe l3 to eductor IS, in which this liquid acts to draw in from the liquid bodyintank l andtodischargeintoreceiver 6 a supply of liquid at least equal to the total quantity required to supply the pump. Any excess quantity raised by the eductor returns through pipe II to tank I.

This feed to the receiver is continuous so long as the pump is in operation and the pump suction is thus maintained in a flooded condition and vaporization in the pump suction is prevented. When the pump is stopped, the receiver remains filledtotheleveltowhiehitisdrainedby pipe I 6. As the liquid in the receiver is in vapor pressure equilihrimn with the liquid in the tank, the

contents of the receiver cannot escape other than by siphoning through pump 1 and pipe i3, and this siphoning is inhibited by forming this pipe in the inverted U-bend shown in the drawing.

The eductor. otherwise known as the Jet pump, is a well known piece of apparatus, commercially available in several forms. It is particularly desirable for the dmcribed purpose because of the entire absence of moving parts but I do not restrict my-invention to the use of this device, any simple means by which the energy of a relatively small quantity of liquid at high pressure is made available to lift a larger quantity of liquid against a lower head being the equivalent of the eductor for my purpose.

While I prefer to locate the eductor or other liquid lifting means within the storage tank as shown, it may be placed without and below the tank and have its suction side connected with the tank by piping.

I claim as my invention:

1. A storage and delivery system for highly volatile liquids comprising in combination: a closed storage tank; a closed receiver arranged substantially above said tank; a pipe affording communication between the upper portion of said receiver and said tank; a pump arranged to have its suction flooded by liquid from said receiver; a liquid-actuated lifting means arranged below the liquid level in said tank and in unimpeded communication with the liquid body therein, said lifting means discharging into the upper portion of said receiver; a pipe aflording communication between the discharge of said pump and the actuating-liquid intake of said lifting means; means for maintaining pressure on the discharge of said pump and within said pipe, and a second pipe afl'ording communication between the discharge of said lifting means and said receiver.

2. A storage and delivery system for highly volatile liquids comprising in combination: a closed storage tank; a closed receiver arranged substantially above said tank; a channel connecting the upper part of said receiver with said tank; a pump arranged to have its suction flooded by liquid from said receiver; a liquid-actuated lifting means arranged adjacent the bottom of said tank and in unimpeded communication with the liquid body therein; means for the passage of lifted liquid into the upper portion of said receiver, and means for withdrawing liquid under pressure from the discharge of said pump to actuate said lifting means.

3. A storage and delivery system for highly volatile liquids comprising in combination: a closed storage tank; a pump arranged substantially above said tank; an eductor arranged adjacent the bottom of said tank and in unimpeded communication with the liquid body therein; a channel affording communication between the discharge of said eductor and the suction of said pump, said channel rising above the level of said pump to maintain said pump continuously flooded, and means for withdrawing liquid under pressure from the discharge of said pump for actuating said eductor. 4

4. A storage and delivery system for highly volatile liquids comprising in combination: a closed storage tank; a pump; a liquid-actuated lifting means arranged adjacent the bottom of said tank and in unimpeded communication with the liquid body therein; a channel for the passage of lifted liquid from the discharge of said lifting means into the suction of said pump, said channel rising above the level of said pump to maintain said pump continuously flooded, and means for supplying liquid under pressure to actuate said lifting means.

. HENRY N. WADE. 

